You’ve gotten some great advice from folks more knowledgeable than I on this topic. But I think that UC-Berkeley and Columbia have programs where there are 2 years spent in France and 2 years in the U.S. And there’s the American U. in Paris, though I don’t know what majors it offers.
Is your son particularly interested in French or in France? If the former, there are options in Quebec, and he might also look into options in Belgium, Switzerland, or other francophone countries.
Also, the National Student Exchange has a number of options where students pay their U.S. tuition rate, but then can go to other universities for u to 1 year per school. So he could do multiple exchanges in Quebec by that method, too.